What would be your inference?

Eric notices repeated probes to port 1080. He learns that the protocol being used is designed to allow a host outside of a firewall to connect transparently and securely through the firewall. He wonders if his firewall has been breached. What would be your inference?

A.
The attacker is using the ICMP protocol to have a covert channel

B.
Eric has a Wingate package providing FTP redirection on his network

C.
Somebody is using SOCKS on the network to communicate through the firewall

D.
Eric’s network has been penetrated by a firewall breach